Winemaking is the production of wine, starting with the selection of grapes and other produce, and ending with putting the delicious wine into bottles! Although wine is usually made from grapes, it may also be made from other fruits! Winemaking can actually be divided into 18 different categories….. Harvesting, destemming, crushing, primary (alcoholic) fermentation, pressing, pigeage, cold stabilization, heat stabilization, second fermentation, bulk aging, Malolactic fermentation, laboratory tests, blending, fining, preservatives, filtration, and last but not least, bottling! Lets now find out how to make wine!
Harvesting is the picking of the grapes and the first step in wine production. The grapes are either harvested by hand or mechanically, the decision lies on the winemaker. Before harvesting, the winemaker checks the grapes for ripeness, flavor, seed color and taste, and lastly, the sugar level! Mechanical harvesters are large tractors that straddle grapevines, and with a rubber rod, strike the vine to get the grapes. Mechanical harvesters have the advantage of picking grapes in a short amount of time. The disadvantage is all the leaves and stems come with the grapes. Some smart winemakers take off the leaves with another machine before harvesting.
Destemming is the process of removing the stems from the grapes. This process may take place before, or after crushing, depending on the winemaker. If you harvest by hand, you can just skip this step altogether!
Crushing is when gently crushing the grapes and breaking the skin to start getting flavor. In traditional and small wineries the grapes are sometimes crushed by stomping on them. However, in large, more upscale wineries, the grapes are crushed by a large, mechanical, wine crusher. Primary (alcoholic) fermentation
Have you ever wondered what the powdery coating around grapes is? So have I! Yeast is what the powder is, which is useful for alcoholic fermentation. Since this can give unpredictable results, cultural yeast is added to the mix. During fermentation, the yeast cells feed on the sugars and multiply, creating carbon dioxide gas and alcohol. The tempeture affects both the taste of the product and the speed that fermentation is over. For red wines, the temperate is typically 72-77 F, and for white wine, the normal tempeture is 59-64 F. For every gram of sugar that is converted, about half a gram of alcohol is produce, so to get a 12% alcohol concentration, the product has to contain 24% of sugar.
Pressing is the act of applying pressure to grapes in order to separate wine from grapes and grape skins. Presses act by positioning the grapes or grape skins between a rigged surface and a movable surface and slowly decreasing the volume between the two surfaces. As the pressure increases, the amount of tannin extracted from the skins into the juice also increases.
Pieaege is a French winemaking term for the traditional stomping of the grapes in open fermentation tanks. To make different type of wine, grapes are put through a crusher and then poured into open fermentation tanks. Once fermentation begins, the grape skins are pushed to the surface by carbon dioxide gases, released in the fermentation process. The layer of skins at the top is called the cap. The cap needs to mix with the liquid each day for flavor Cold and Heat Stabilization
Cold stabilization is a process used in winemaking to reduce tartrate crystals that’s in wine. These crystals look like grains of clear sand, and are formed by acid and potassium. The temeture of the wine is dropped close to freeing for 1-2 weeks. This will cause the crystals to separate from the wine. During heat stabilization, unstable proteins are removed by absorption, preventing them from being in the finished bottle of wine.
This process takes three to six months, and is very valuable! The wine is kept under airlock, and proteins from the grapes are broken down, and the yeast cells that are still remaining and other particles are able to settle. In this process, the wine goes from being cloudy, to clear! Secondary fermentation usually takes place in large stainless steel vessels or large oak barrels. The oak gives wine a very good finished taste, but if the winemakers decide to put the wine in stainless steel, oak chips are added!
This process occurs when lactic acid bacteria mixes with malic acids and produces lactic acids and carbon dioxide. Malolatic fermentation can improve the taste of wine that has large amounts of malic acids. Malic acids creates an unpleasant, harsh, and bitter taste sensation. All red wines go through malolatic fermentation to lessen the amount of acid in the wine, and to remove the possibility that malic acids may be in the bottle. On the other hand, many white wines do not go through fermentation, because they don’t have a lot of acid.
Whether wine is stored in vessels or barrels, tests are done regularly. These tests are done to test sugar level, alcohol level, pH level, and many other factors. Theses tests are performed throughout the making of the wine, from the first step through the last!
Blending and Fining
Different wines can sometimes be mixed together to achieve the desired taste. This process is as simple as the tests the wine have, every now and then. Fining is removing the chemicals and particles that make the wine cloudy. Gelatin has actually been used in many wines for centuries, as a traditional method for wine fining! Usually, no gelatin actually remains in the wine, as it mixes with other chemicals. Also many fining agents will use milk, eggs, bone char, bulls blood, an animals bladder, honey, and a skim milk powder.
The most common preservative in winemaking is sulfur dioxide. Sulfur dioxide has one main reason, and that is that its an anti oxidant. If sulfur dioxide is added before alcoholic fermentation, it may damage the effects of oxygen, and the wine will go bad! Without the use of sulfur dioxide, wines will suffer bacterial spoilage. Some winemakers practice natural winemaking where no preservatives are added. The wine is then put in a freezer with the temperature being 5 C.
Filtration in winemaking is used to accomplish two objectives: clarification and stabilization. In clarification, large particles that effect the visual appearance of the wine are removed. In stabilization, organisms that effect the stability are removed, therefore killing all possibilities of the wine going bad. The wine is then put in the refrigerator at a low temperature.
Finally, the last step in winemaking! A final does of sulfite is added to help preserve the wine and to prevent unwanted fermentation going on in the bottle. Once the wine bottles are filled,, they are traditionally sealed with a cork. The final step is adding a capsule!
The wine is now ready to be shipped off, and then sold to buyers that will greatly enjoy the taste! Many people actually don’t know how much work is put into making the wine! That’s why its so expensive, nowadays! I hoped I helped you to understand the process of…………. WINEMAKING!!!!!